In the first case to reach the Supreme Court arising from the blitz of actions taken in the early weeks of the new administration, lawyers for President Trump asked the justices on Sunday to let him fire a government lawyer who leads a watchdog agency.

The administration’s emergency application asked the court to vacate a federal trial judge’s order temporarily reinstating Hampton Dellinger, the head of the Office of Special Counsel. Mr. Dellinger leads an independent agency charged with safeguarding government whistle-blowers and enforcing certain ethics laws. The position is unrelated to special counsels appointed by the Justice Department.

“This court should not allow lower courts to seize executive power by dictating to the president how long he must continue employing an agency head against his will,” the administration’s filing said.

The court is expected to act in the coming days.

The filing amounts to a challenge to a foundational precedent that said Congress can limit the president’s power to fire leaders of independent agencies, a critical issue as Mr. Trump seeks to reshape the federal government through summary terminations.

The statute that created the job now filled by Mr. Dellinger, who was confirmed by the Senate in 2024, provides for a five-year term and says the special counsel “may be removed by the president only for inefficiency, neglect of duty or malfeasance in office.” But a one-sentence email to Mr. Dellinger on Feb. 7 gave no reasons for terminating him, effective immediately.